It is understood Mr. Whitman in 1962 in his U.S. Pat. No. 3,043,009, provided plastic trays to create standard structural bases or art portions, to thereafter receive dental casts, and thereby eliminate the need for making full display dental casts with bases trimmed by using rotary grinders.
Then in 1974 Robert Hudson and John Richards in their U.S. Pat. No. 3,823,476 in addition to providing plastic trays, provided a pivotal connection between such trays creating a hinge motion to simulate the relative movement of a patient's upper and lower jaws.